The present invention relates to a salt-sand spreader which will coat particles with a liquid as the particles are discharged to inhibit corrosive action of salt as well as to provide for an initial acceleration of melting of ice on a roadway.
At the present time in cold climates, it is common for highway departments to spread large amounts of salt, and salt-sand mixtures during freezing weather when packed snow and ice accumulate on roadway surfaces in order to melt away the ice and avoid excessive slippery conditions.
When salt is deposited, the reaction with ice takes some time before the ice forms a solution that is sufficiently concentrated to remain liquid at temperatures below the melting point of ice. Additionally the salt solution liquid is highly corrosive, and has long been a source of damage to automobiles and other vehicles by causing rust.
Another problem with existing spreaders, which generally use a disk-type rotor rotating about a generally upright axis is that the particles will bounce on the roadway and not remain in the position desired. This is primarily caused by differentials in speed between the particles and the road surface when they strike the surface. While tremendous volumes of sand and salt are spread on the roadways each year, the problems associated with such spreading, and which further include environmental damage, have been unsolved. U.S. Pat. No. 4,886,208 teaches applying a liquid to fertilizer particles that are carried in a fluid in tubes.